Oxygen saturation measuring sensor, and oxygen saturation measuring apparatus

Abstract

An oxygen saturation measuring sensor is capable of increasing reliability of information of parts having different depth and includes a pad attachable to a human body; plural light sources arranged on the pad to be adjacent in a separate state, and irradiate near-infrared light; plural light receiving elements arranged on the pad to be adjacent in a separate state and correspond one to one to the plural light sources with reference to a common center with an innermost side of the plural light sources, and that receive transmitted light from the corresponding plural light sources; and a ROM unit that stores a reference value through measuring transmitted light using a phantom in advance and stores a light receiving amount of the transmitted light received by the plural light receiving elements.

The invention claimed is: 
     
       1. An oxygen saturation measuring sensor comprising:
 a pad attachable to a human body; 
 a plurality of light sources comprising a light source A and a light source B arranged on the pad adjacent to and spaced apart from one another, and that irradiate near-infrared light; 
 a plurality of light receiving elements comprising a light receiving element A and a light receiving element B arranged on the pad adjacent to and spaced apart from one another and correspond one to one to the plurality of light sources with reference to a common center between 1) the light sources A and B, and 2) the light receiving elements A and B, and that receive transmitted light from the corresponding plurality of light sources, wherein distances between 1) the light source A and the light source B, 2) the light source B and the light receiving element B, and 3) the light receiving element A and the light receiving element B are the same; and 
 a ROM unit that stores a reference value through measuring transmitted light using a phantom in advance. 
 
     
     
       2. The oxygen saturation measuring sensor according to  claim 1 , wherein
 the pad includes a printed substrate having an attachment surface configured to be attached to the human body and a foamed rubber provided on a back surface side of the printed substrate, wherein a light source of the plurality of light sources and a light receiving element of the plurality of light receiving elements are arranged in a hole formed in the printed substrate such that a surface of the light source and a surface of the light receiving element have the same plane as the attachment surface. 
 
     
     
       3. The oxygen saturation measuring sensor according to  claim 1 , wherein
 sensor A comprises the light source A and light receiving element A and sensor B comprises the light source B and light receiving element B, and 
 sensors A and B measure the information at different depths below the common center. 
 
     
     
       4. The oxygen saturation measuring sensor according to  claim 3 , wherein information at a depth measured by the sensor B is subtracted from information at a depth measured by the sensor A. 
     
     
       5. The oxygen saturation measuring sensor according to  claim 4 , wherein the sensors A and B each measure the information at their respective depths having a length of 70% to 80% of a distance between the light source and the light receiving element. 
     
     
       6. An oxygen saturation measuring apparatus comprising:
 a sensor unit; and 
 a main body, wherein 
 the sensor unit comprises:
 a pad attachable to a human body; 
 a plurality of light sources comprising a light source A and a light source B arranged on the pad adjacent to and spaced apart from one another, and that irradiate near-infrared light; 
 a plurality of light receiving elements comprising a light receiving element A and a light receiving element B arranged on the pad adjacent to and spaced apart from one another and correspond one to one to the plurality of light sources with reference to a common center between 1) the light sources A and B, and 2) the light receiving elements A and B, and that receive transmitted light from the corresponding plurality of light sources, wherein distances between 1) the light source A and the light source B, 2) the light source B and the and the light receiving element B, and 3) the light receiving element A and the light receiving element B are the same; and 
 a ROM unit that stores a reference value through measuring transmitted light using a phantom in advance, and 
 
 the main body comprises:
 an arithmetic processing unit that calculates actual absorbance on the basis of a light receiving value and a reference value regarding an amount of receiving light stored by the ROM and computes an oxygen state of a living body to comply with the Beer-Lambert law while comparing the reference value.